Synthesis, Characterization, and Properties of Large-Area Graphene Films

Graphene and few-layer graphene films exhibit unique properties and show promise as electronic devices as well as for passive applications. A significant challenge however is the synthesis of large area graphene and/or multilayer films. A method that is showing promise is the growth of graphene on metal substrates by chemical vapor deposition. In this paper we report on a method to grow large-area graphene films on Cu foils and graphene transfer methods to other substrates. The transferred graphene films were characterized by optical, scanning and transmission electron microscopy, Raman and UV-VIS spectroscopy, and four-point probe electrical measurements. The data shows that graphene can be grown directly on Cu substrates by chemical vapor deposition. The graphene films transferred to SiO2/Si substrates show low defects as determined by the near absence of the "D" band at 1350 cm-1 in the Raman spectrum. In addition, the films were found to have high optical transmittance and electrical conductivity.